Working Principle Of Buokhloz Relay

How to Buokholz relay protect the transformer

How to Buokholz relay protect the transformer, The transformer is an oil container is connected with the main tank to conservator tank.  There are basically two parts one is the upper float. The upper float is connected with the hinge such a way that it can move up and down depending on the oil level pressure in the Buchholz relay in the container. For upper float, a mercury switch is connected to the float and the switch is depends on the upper float. Any movement of float the switch will work. The upper float is working only for the minimum level of the transformer. It means when the oil fault occurs inside the transformer like oil leakage. When the oil gets out from the transformer for leakage fault. The result is fall of the oil level. When the oil fault occurs it will make a displacement of the upper float goes downward and its connected with the mercury switch and switch is connected to the alarm circuit. When oil fall increases the float goes down and the mercury switch is closed Moreover the alarm circuit will be energized. The relay takes place for the oil fault.How to Buokholz relay protect the transformer

This gas is released by the gas release path which is top on the transformer and the gas release path sense which type of fault is occurring inside the transformer.

Lower Float of Buchholz Relay

The lower float is working when a serious fault occurs inside the transformer like a short circuit between phases or to earth and fault in tap changing inside the transformer. Equipment is accompanied by a surge of oil which sticks the buffer plate and the result of close the mercury switch and trip the transformer.

Main Working Principal of Buchholz relay

The operation of Buchholz relay is very simple. It is based on the mechanical phenomenon. It is mechanically actuated whenever there will be a minor fault inside the transformer. Such as insulation fault between turns, core heating, breakdown of the core of the transformer. When a fault occurs inside the transformer. Such as insulation failure of turns, the breakdown of core excess heat, the result of oil will be decomposed in different hydrogen gases like carbon mono oxide(CO), carbon-dioxide(CO2) and the gas will produce. The gas draws upwards float and make a displacement of the float and it is connected with the mercury switch. The upper float closes the switch and the alarm circuit gives an alarm.